Liquid and gaseous fuel burner



Dec. 29, 1964 H. L. lHLENFlELD 3,163,203

- LIQUID AND GASEQQSNELLEIL ggggggg Filed Dec. 6, 1961 2 Sheets-Sheet l INVENTOR.

Hmaey 4. [HAEA/F/Elfl Dec- 29, 1964 H. 1.. IHLENFIELD LIQUID AND GASEOUS FUEL BURNER 2 Sheets-Sheet 2 Filed Dec. 6, 1961 INVEN TOR.

Hwaey 4. [f/E/VF/ELO ArraQu/EKS United States Patent 3,163,203 LIQUID AND GAS OUS FUEL BURNER Harry L. lhlenfield, Parma, Ohio, assignor to Brown Fintube Company, Elyria, Ohio, a corporation of Ohio Fiied Dec. 6, 1961, Ser. No. 157,458 2 Claims. (Cl. 158-11) This invention relates to fuel burners and more particularly to high capacity burners adapted to burn either liquid or gaseous fuels, although. they may be manufactured to burn gaseous fuels only.

A general object of the present invention is the provision of a compact, eflicient burner adapted to produce high temperature flame with efiicient combustion and large thermal output in relation to the size of the burner. Another object is the provision of such a burner which can readily be adapted to different purposes and uses. A further object is the provision of such a burner which can be started easily and which can be operated with a clean flame and efilcient' combustion from its full rated capacity down to approximately of its rated capacity. An- 7 other object is the provision of such a burner which has excellent flame retention and freedom from pulsations. A further object is the provision of a burner of this character which can be switched from gaseous to liquid fuel and vice versa with a minimum of difficulty. A further object is the provision of burners of these characteristics which can be manufactured economically, which are of sturdy construction, and which are simple and dependable in operation. Other objects and advantages of the invention will become apparent from the following description of a preferred form thereof, reference being made to the accompanying drawings in which:

FIGURE 1 is a longitudinal elevation, with parts broken away in vertical section, of a preferred form of burner embodying the invention;

FIGURE 2 is a sectional elevation of the burner shown in FIGURE 1, the view being taken along line 22 of FIGURE 1 and to a larger scale;

FIGURE 3 is anothercross sectional elevation of the burner of FIGURE 1, from line 33 of FIGURE 1 and to the scale of FIGURE 2; and

FIGURE 4' is a sectional elevation along line 44 of FIGURE 3 and to a larger scale, of one of the gas apertures and its associated deflecting vane.-

Referring now to FIGURES 1, 2 and 3 of the drawings, the preferred form of the invention shown comprises a cylindrical housing 10 including a peripheral cylindrical-wall 11, a front wall 12 at the front end of wall 11, a rear wall 13 closing the rear portion of the housing 10, and an intermediate wall 14 located between front wall 12 and rear wall 13 at approximately a third of the distance between front wall 12 and rear Wall 13. The front wall 12, intermediate wall 14, and the forward portion, of peripheral Wall 11 thus define a front chamber 15; the intermediate wall 14, rear Wall 13, and rear portion of peripheral Wall 11 thus define another chamber 16. A gas inlet member 17, adapted to be connected to a supply of gaseous fuel, opens laterally into the portion of peripheral wall 11 defining chamber 16.

A cylindrical elongated air supply conduit member 18 extends coaxially of housing 19 from the rear. of the burner through rear wall 13, chamber 16, and intermediate wall 14 of housing 10 into the front chamber 15. The front or discharge end of conduit member 18 projects beyond intermediate wall Hand is located relatively near front wall 12. The part of conduit member 18 located outside of housing 10 has a laterally extending air inlet member 19, adapted to be connected to a source of air under higher than atmospheric pressure,

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and. a rear closure member 20 held in place by set screws 21. v Conduit member 18 coaxially supports a pipe 22 the rear end of which projects rearwardly from and is supported by closure member 20 of member 18, and the front end of which extends through an opening 23 in front wall 12 and is supported by radially extending members 24 fixed to the exterior of pipe 24 near its front end and engaging the inner Wall of conduit member 18. Pipe 22 has mounted coaxially therein a tube 25 for supplying liquid fuel. .The rear portion of tube 25 is mounted in and projects from a plug 26 threaded into a fitting 27 screwed on the end of pipe 22 projecting from conduit 18; fitting 27 supports the rear end of liquid fuel supply tube 25, and also provides an inlet portion 28 through which air may be laterally introduced into pipe 22. The front portion of pipe 22 forms part of a liquid fuel burner generally indicated by numeral 30 and comprising a female nozzle member 31 fixed. in the end of pipe 22 and surrounding and spaced from a male nozzle member 32 mounted on the front end of tube 25; this burner which may be of conventional construction, acts in the conventional manner to eject a mixture of air and finely divided liquid fuel'into the combustion zone.

The front end of pipe 22 supports a closure plate member 33 adapted to close the opening 23 in front wall 12, and this forms the central portion of the front wall. An air metering member 34, comprising a circular plate portion 35 fixed to a hub 36, is adjustably mounted on the exterior of pipe 22 by set screw 38. By selection of the appropriate diametrical size of plate portion 35' and by proper location of it along pipe 22 relatively to the front wall 12 and the discharge end of conduit 18, it is possible to control closely the quantity andflow pattern of air into the interior of chamber 15 in housing10.

As shown in FIGURES 1, 3 and 4, the major portion of the front wall 12 is a sheet metal plate 37 having the central opening 23 and a circular periphery which closely fits in the front opening of peripheral wall11, being held in place by bolts 33 threadedinto lugs 40' welded to the inner surface of wall 11. The plate 37 is'apertured by twelve rectangular slots 41 each approximately half as wide as it is long, each of the slots being located with its long side at an angle A, 30 in the illustrated embodiment, to a radius line passing through'a corner of the slot; furthermore as shown in FIGURE 4, each of the slotsat one of its long sides has a deflecting vane 42 which projects at an angle B, approximately 45 in the illustrated case, from the plane of the outer surface of plate 37; the projection of each vane into such'plane substantially covers the associated slot. By this design, the mixture of air and fuel gas forced'through the angular slots is caused to travel in a swirling, helical path into and through the combustion zone.

In the illustrated apparatus, a number of nozzle members 43 are located with their discharge ends 44' Within front chamber 15 in close proximity to the inner surface of the front wall 12 and also to the slots 41. The

rear of each nozzle member extends through and is supported by the intermediate wall 14 of the housing 10, l

and has an inlet 45 communicating with the interior of chamber 16. The number of nozzle members 43 may be equal to, greater than, or less than the number of slots 41 in the front wall 12;.in the illustrated embodiment, there are sixteen nozzle members 43 equally spaced around a circle coaxial with peripheral wall 11, conduit member 18, pipe 21 and tube 25'. Preferably, as in the illustrated embodiment, the discharge ends of the nozzle members 43 are located soclose to front wall 12 and slots 41 that gaseous fuel discharging from the nozzle members mixes with air discharging from conduit mem- Patented Dec. 29, 1964-.

ber 18 as the fuel and air both pass through the slots 41, the resulting mixture being discharged from the slots in a helical swirling path due to the action of the vanes 42. Little if anyintermixing between the gas and air occurs within chamber 15; the gas and air are very thoroughly intermixed as they pass throughthe, slots 41 and are deflected by vanes 42. p a

The front of housing 10 rigidly carries a flange 46, the circular outer edge of which rigidly supports a frustoconical sleeve 47 terminating in a rigid, radially outwardly extending flange 48 by which the burner maybe mounted on the heat exchanger or other device with which it is to be used. The mounting of the burner at its front end only eliminates problems due to expansion and contraction of the burner under heat. The cup-shaped receptacle provided by flange 46 and sleeve 47 firmly supports a liner 49 of refractory material forming the walls of com- The design is such that old liners of refractory material can be removed and replaced by new liners as desired,

without extensive disassembly or re assembly of the burner.

As shown in FIGURES 1 and 3, the sleeve 47 supports several angularly disposed sockets 52,53 and 54 adapted to carry elements such as the observation port, pilot, and flame rod ho'lder; since these items may be of conventional construction, they are not shown. The pipe 22 may also support a conventional photocell control unit 55 adapted to see, through openings 56 and 57 in members 33 and 35, the flame from the burning of liquid fuel, in the conventional manner. Thus, desirable safety and control features may be employed in connection with this burner.

' high degree of efficiency and with smoke-free and soot-j When the burner is operated on gaseous fuel, such as passes through the inclined slots 41 into the combustion chamber 51. Meanwhile suitable gaseous fuel is introduced, at a pressure of about 2 ounces per sq. inch higher than the air pressure, through gas inlet member 17 into the chamber 16 in housing 10, from which the gas passes through the nozzle members 43 and is discharged from their discharge ends 44. The discharged gas is substantially immediately entrained by and intermixed with the air flowing into and through the inclined slots 41. After the air-gas mixture has been ignited by the conventional pilot, which may be turned off after this flame has been ignited or may be left on if desired, a helical swirling flame results which tends to wipe the surrounding outer walls. This flame, which may be several feet long, thus provides exceptional efliciency in heat exchangers of the fired finned tube type, since the flame wipes the inner surface of the finned inner tube for a considerable length. The flame is clean and remarkably soot-free. Combustion is extremely eflicient, as shown by the fact that it is possible to obtain in the exhaust gases a high carbon dioxide output with very little carbon monoxide. It is possible to obtain a highly reducing atmosphere in the products of combustion, which is advantageous in eliminating orreducing corrosion of enclosures containing the flame. The burner provides excellent flame retention and remarkable freedom from pulsation. High heating efficiencies, and smoke-free and soot-free combustion therefore can be providedby the burner. Furthermore, it is possible to operate such a burner at as low as 10% of its maximum rated capacity, while maintaining efiicient operation and smoke-free and soot-free combustion For these reasons, the burnercan operate for long periods of time with little attention while burning gaseous fuel.

When it is desired to operate the burner on liquid fuel, such as one of the usual petroleum oils, the supply of gas into inlet member 17 is cut off, and the pilot, if burning, is extinguished. Air is caused to flow into inlet member 19 and through conduit 18 in the usual manner, but air also is causedto flow into inlet member 28 and pipe 22.. Liquid fuel is supplied through tube 25 by suitable regulating means. The mixture of finely divided liquid fuel and air emitted by the burner 30 into the combustion chamber 51'is ignited by conventional means.

The resulting flame, supported by the secondary air in. troduced into the combustion chamber in a swirling helical path through the vaned slots 41, travels in a helical swirling path for a considerable distance, during which tion, such advantages including high combustion effi-.

ciency, production of a reducing atmosphere if desired, a clean soot-free flame, excellent flame retention and freedom from pulsations, and long periods off-operation.

without need for attention or cleaning. Furthermore, even while using liquid fuel, the burner can be caused to operate at only about 10% of its maximum output, with gaseous fuel or liquid fueL making' possible greater flexibility in operations, greateropportunities to take ad-- vantage of relative fuel economies, and the prevention of production losses if one of the fuels should become unavailable. The burners of .the invention are simple and sturdy and can be manufactured at reasonable cost;

they may be used for a wide variety of purposes, being particularly adapted for preheating air. They require little attention and are substantially foolproof 'in operation.

Moreover, the maximum heat output capacity of the; burner of the invention can be readily changed. By merely loosensing set screws 21, the entire subassembly comprising pipe 22, liquid fuel burner 30,. front closure plate 33, air metering member 34 and rear closure member 20 can be removed rearwardly from the remainder of the burner assembly. The location of metering member 34 along pipe 22 can be readily adjusted, which has a'bear-.

ing on burner efficiency; or, after the front plate 33 is first temporarily removed by loosening its set screw 58,

the air metering member 34 may be removed and re-. placed by one having a plate 35 of different outerv diame-.

Within easily determinable limits, a member'34 ter.

' with a larger plate 35 passes less secondary combustion air and thus reduces the heat output of the burner, while a member 34with a smaller plate 35 will pass more secondary air and increases heat output. This occurs for both liquid or gaseous fuels, but is particularly. pronounced with gaseous fuel.

Moreover, if desired, with the subassembly thus re; moved liquid fuel burner nozzle 30 may be adjusted or changed to change the volume or pattern of liquid fuel emitted and thus to change the heat capacity of the burner when it operates onliquid fuel. It'is therefore possible for the manufacturer readily to support burners embodying the invention but having different capacities, by making identical the major portions of the burners and effecting the above indicated simple internal changes,

and for the user to change the maximum heating capacity of a burner of the invention as required for certain uses by making similar simple internal changes.

Furthermore, by the above indicated disassembly, and

- by removal of. apertured plate 37 after removal of its When operating on Moreover, the burner can be designed to Removal of plate 37 particularly makes possible inspection or replacement of the nozzle members 43. Obviously the burner may be easily reassembled after such disassembly.

Various changes and modifications other than those indicated above may be made in the preferred embodiment of the invention without departing from the spirit and scope of the invention. It is therefore to be understood that the form of invention described in detail herein is given by way of example, and that the scope of the invention is defined by the appended claims.

I claim:

1. In a fluid fuel burner for selectively burning liquid or gaseous fuel, a first elongated conduit member having a front and a rear end; an outer housing surrounding the front portion of said first conduit member, said housing having a peripheral wall extending generally axially of said first conduit member beyond the front end thereof, said housing being closed at its rear portion by being joined to said first conduit member at a location such that the rear portion of said first conduit member projects rearwardly beyond said housing, said housing including an intermediate wall connecting said generally axially extending wall of said housing and the exterior of said first conduit member at a location forward of the rear portion of said housing and near the front end of said first conduit member to define a gaseous fuel chamber; means for supplying gaseous fuel to said chamber; a front Wall closing the front of said housing to define, with said intermediate wall and the front portion of said first conduit member, a front chamber in said housing into which said first conduit member discharges, said front Wall having therein a plurality of openings spaced around said front wall, said openings having associated therewith angularly disposed surfaces adapted to deflect gases discharging througa said openings. into a generally helical path extending away from said front wall; means defining a passageway providing a space at the side of said front wall opposite said front chamber, into which space gas is discharged from said openings in said front Wall; a plurality of nozzle members having inlets opening through said intermediate wall into said gaseous fuel chamber and having outlets located in said front chamber near the openings in said front wall to discharge gmeous fuel so it can pass through said openings directly into said space in said passageway; a second conduit member extending from beyond the rear end of said first conduit member, through said first conduit member, and through said front chamber, the front end of said second conduit member discharging through said front wall; a liquid fuel nozzle disposed adjacent the front end of said second conduit member; means for supplying liquid fuel to said nozzle; means for supplying air to said first conduit memher through the portion thereof projecting rearwardly beyond the rear portion of said housing; and a metering member mounted on said second conduit member within and near the front end of said first conduit memher to control the flow of air from said first conduit member into said front chamber. i 2. In a fluid fuel burner for selectively burning liqui or gaseous fuel, a first elongated conduit member having a front end and a rear end; an outer housing surrounding the front portion of said first conduit member, said housing having a peripheral Wall extending generally axially of said first conduit member beyond the front end thereof, said housing being closed at its rear portion by being joined to said first conduit member at a location such that the rear portion of said first conduit member projects rearwardly beyond said housing, said housing including an intermediate wall connecting said generally axially extending wall of said housing and the exterior of said first conduit member at a location forward of the rear portion of said housing and near the front end of said first conduit member, to define a gaseous fuel chamber; means for supplying gaseous fuel to said chamber; a front wall closing said housing to define, with said intermediate wall and the front portion of said first conduit member, a front chamber in said housing into which said first conduit member discharges, said front wall having therein a plurality of openings spaced around said front Wall, said openings having associated therewith angularly disposed surfaces adapted to deflect gases discharging through said openings into a generally helical path extending away from said front wall; a plurality of nozzle members having inlets opening through said intermediate Wall into said gaseous fuel chamber and having outlets located in said front chamber near the openings in said front wall so that substantially all gaseous fuel discharged from said nozzle members passes through said openings in said front wall; a second conduit memberextending from beyond the rear portion of said housing, through said first conduit member, and through said front chamber, the front end of said second conduit-member discharging through said front wall; a liquid fuel nozzle disposed adjacent the front end of second conduit member; means for supplying liquid fuel to said nozzle; means for supplying air to said first conduit member through the portion thereof projecting rearwardly beyond the rear portion of said housing; and a metering member mounted on said second conduit member within and near the front end of said first conduit member to control the flow of air from said first conduit into said front chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,711,982 Argo et al May 7, 1929 1,797,570 Ferguson Mar. 24, 1931 1,969,157 Shoenberger Aug. 7, 1934 2,932,347 Jaeger Apr. 12, 1960 2,973,032 Reilly et a1. Feb. 28, 1961 3,032,097 Marshall May 1, 1962' 3,076,497 Robb Feb. 5, 1963 

1. IN A FLUID FUEL BURNER FOR SELECTIVELY BURNING LIQUID OR GASEOUS FUEL, A FIRST ELONGATED CONDUIT MEMBER HAVING A FRONT AND A REAR END; AN OUTER HOUSING SURROUNDING THE FRONT PORTION OF SAID FIRST CONDUIT MEMBER, SAID HOUSING HAVING A PERIPHERAL WALL EXTENDING GENERALLY AXIALLY OF SAID FIRST CONDUIT MEMBER BEYOND THE FRONT END THEREOF, SAID HOUSING BEING CLOSED AT ITS REAR PORTION BY BEING JOINED TO SAID FIRST CONDUIT MEMBER AT A LOCATION SUCH THAT THE REAR PORTION OF SAID FIRST CONDUIT MEMBER PROJECTS REARWARDLY BEYOND SAID HOUSING, SAID HOUSING INCLUDING AN INTERMEDIATE WALL CONNECTING SAID GENERALLY AXIALLY EXTENDING WALL OF SAID HOUSING AND THE EXTERIOR OF SAID FIRST CONDUIT MEMBER AT A LOCATION FORWARD OF THE REAR PORTION OF SAID HOUSING AND NEAR THE FRONT END OF SAID FIRST CONDUIT MEMBER TO DEFINE A GASEOUS FUEL CHAMBER; MEANS FOR SUPPLYING GASEOUS FUEL TO SAID CHAMBER; A FRONT WALL CLOSING THE FRONT OF SAID HOUSING TO DEFINE, WITH SAID INTERMEDIATE WALL AND THE FRONT PORTION OF SAID FIRST CONDUIT MEMBER, A FRONT CHAMBER IN SAID HOUSING INTO WHICH SAID FIRST CONDUIT MEMBER DISCHARGES, SAID FRONT WALL HAVING THEREIN A PLURALITY OF OPENINGS SPACED AROUND SAID FRONT WALL, OPENINGS HAVING ASSOCIATED THEREWITH ANGULARLY DISPOSED SURFACES ADAPTED TO DEFLECT GASES DISCHARGING THROUGH SAID OPENINGS INTO A GENERALLY HELICAL PATH EXTENDING AWAY FROM SAID FRONT WALL; MEANS DEFINING A PASSAGEWAY PROVIDING A SPACE AT THE SIDE OF SAID FRONT WALL OPPOSITE SAID FRONT CHAMBER, INTO WHICH SPACE GAS IS DISCHARGED FROM SAID OPENINGS IN SAID FRONT WALL; A PLURALITY OF NOZZLE MEMBERS HAVING INLETS OPENING THROUGH SAID INTERMEDIATE WALL INTO SAID GASEOUS FUEL CHAMBER AND HAVING OUTLETS LOCATED IN SAID FRONT CHAMBER NEAR THE OPENINGS IN SAID FRONT WALL TO DISCHARGE GASEOUS FUEL SO IT CAN PASS THROUGH SAID OPENINGS DIRECTLY INTO SAID SPACE IN SAID PASSAGEWAY; A SECOND CONDUIT MEMBER EXTENDING FROM BEYOND THE REAR END OF SAID FIRST CONDUIT MEMBER, THROUGH SAID FIRST CONDUIT MEMBER, AND THROUGH SAID FRONT CHAMBER, THE FRONT END OF SAID SECOND CONDUIT MEMBER DISCHARGING THROUGH SAID FRONT WALL; A LIQUID FUEL NOZZLE DISPOSED ADJACENT THE FRONT END OF SAID SECOND CONDUIT MEMBER; MEANS FOR SUPPLYING LIQUID FUEL TO SAID NOZZLE; MEANS FOR SUPPLYING AIR TO SAID FIRST CONDUIT MEMBER THROUGH THE PORTION THEREOF PROJECTING REARWARDLY BEYOND THE REAR PORTION OF SAID HOUSING; AND A METERING MEMBER MOUNTED ON SAID SECOND CONDUIT MEMBER WITHIN AND NEAR THE FRONT END OF SAID FIRST CONDUIT MEMBER TO CONTROL THE FLOW OF AIR FROM SAID FIRST CONDUIT MEMBER INTO SAID FRONT CHAMBER. 